write from a specific column

Question

In my piece of code, I have,

 out.write(datGroup)
 out.write(' '*20+": Space Group\n")
 out.write(datLatx +"  ") 
 out.write(datLaty +"  ") 
 out.write(datLatz +"  ") 
 out.write('/'),     
 out.write(' '*20+": a,b,c,alpha,beta,gamma\n")

which gives the output as:

189                    : Space Group
10  11  12  /                    : a,b,c,alpha,beta,gamma

which is correct for what I have done, but not what I have want.

I want the ": Spacegroup" and ": a,b,c.." to start from the same column, irresepective of where the data of its row ended, like:

189                    : Space Group
10  11  12  /          : a,b,c,alpha,beta,gamma

Can I do that in python3?

EDIT after jonrsharpe's example So I have tried:

  def write_row(out, data, header, col=20):
    out.write("{0}: {1}".format(" ".join(map(str, data)).ljust(col), header))

  def print_data(self, BSub):
  .....
   with open("Init", mode='w') as out:
     write_row(out, (datGroup,), "Space Group")

which is giving error:

$ python3 geninit.py 
Traceback (most recent call last):
  File "geninit.py", line 109, in print_data
    write_row(out, (datGroup,), "Space Group")
NameError: global name 'write_row' is not defined

@jonrsharpe has given a brilliant example. It is precisely what I was taking about. You should check it out. — sshashank124
– sshashank124, Commented Apr 9, 2014 at 10:04

jonrsharpe · Accepted Answer · 2014-04-09 10:08:55Z

2

I would create a function to do this, for example:

def print_row(data, header, col=20):
    print("{0}: {1}".format(" ".join(map(str, data)).ljust(col), header))

Then call it for each case:

print_row((datGroup,), "Space Group")
print_row((datLatx, datLaty, datLatz), "a,b,c,alpha,beta,gamma")

This gives, for example

>>> datGroup = 189
>>> datLatx, datLaty, datLatz = 11, 12, 13
>>> print_row((datGroup,), "Space Group")
189                 : Space Group
>>> print_row((datLatx, datLaty, datLatz, "/"), "a,b,c,alpha,beta,gamma")
11 12 13 /          : a,b,c,alpha,beta,gamma

This uses:

map(str, ...) to convert all of the data into strings;
" ".join(...) to put spaces between the data items;
str.ljust to pad the left "column" with spaces, keeping it the same width; and
str.format to put the padded left column and the header around the ": ".

You can then adapt this to write to your output file (which you could pass as an argument) rather than print the data, e.g.:

def write_row(out, data, header, col=20):
    out.write(...)

and call

write_row(out, (datGroup,), "Space Group")

edited Apr 9, 2014 at 10:08

answered Apr 9, 2014 at 9:55

jonrsharpe

123k31 gold badges277 silver badges488 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

BaRud Over a year ago

Thanks for your detailed example, but as for a newbie, can you kindly show how to adopt this for write?

jonrsharpe Over a year ago

@BaRud I have added a skeleton function and example call to the end of the answer

Collectives™ on Stack Overflow

write from a specific column

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related